This invention relates to velour fabric articles, and, more particularly, to velour fabric articles having improved dynamic insulation performance due to relatively greater densification and tortuosity, and improved flame retardance.
Velour fabric articles having one or more fleece or raised surface regions at one surface or at both surfaces, e.g., achieved by processes of sanding, brushing and/or napping of exposed fibers, are known to have good insulation performance under static conditions, i.e., in calm or still air with no wind blowing through the fabric. However, the insulating performance of these fabric articles drops rapidly under dynamic conditions, i.e., in a chilling wind. As a result, a consumer wearing a velour fabric article will often find it necessary to also wear a shell, e.g., of woven nylon or other low permeability material, when conditions are likely to be windy.
It is also known to increase the thermal insulation performance of velour fabric articles by incorporating a relatively coarser stitch yarn and/or by tightening the stitch. However, these approaches result in fabric articles with very poor stretch, increased stiffness and increased weight.
According to one aspect of the invention, a double-face velour fabric article comprises a fabric body having a technical face formed by a filament stitch yarn and a technical back formed by a loop yarn, the filament stitch yarn comprising heat sensitive material and the loop yarn comprising flame retardant material, the fabric body having a velour surface formed at one or both of the technical back and the technical face, and the heat sensitive material responding to application of heat during processing to increase tortuosity with a result of the fabric body having permeability of about 90 ft3/ft2/min or less under a pressure difference of xc2xd inch of water across the fabric body (according to the testing method of ASTM Designation: D 737-96, xe2x80x9cStandard Test Method for Air Permeability of Textile Fabrics,xe2x80x9d the entire disclosure of which is incorporated herein by reference).
Preferred embodiments of this aspect of the invention may include one or more of the following additional features. The flame retardant material comprises m-Aramide fibers. The heat sensitive material is preferably selected from the group consisting of polypropylene, polyester, and polyamide. The heat sensitive material comprises heat shrinkable material, preferably selected from the group consisting of polypropylene, nylon, and polyester. The heat sensitive material responds to application of dry heat and/or to application of wet heat, e.g. steam or hot water, e.g. at about 212xc2x0 F. to about 450xc2x0 F. applied for about 2 minutes to about 60 minutes. The filament stitch yarn comprises elastomeric material, e.g. spandex. Filaments of the heat sensitive material and filaments of the elastomeric material are commingled or plaited together. The filament stitch yarn is a cored yarn comprising a core and a sheath, the sheath comprising hot melt material. The core material is preferably selected from the group consisting of polyester and nylon, and the hot melt material is preferably selected from the group consisting of polypropylene, polyester and polyamide. The loop yarn is split, e.g. by application of heat, e.g. the loop yarn of fine denier fibers or filaments comprises an xe2x80x9cislands-in-seaxe2x80x9d construction, or by application of a chemical, e.g. caustic soda, or by mechanical action, e.g. napping, to release multiple small diameter filaments. The loop yarn and/or the filament stitch yarn are textured. Raised fibers of the velour surface, of at least one of the technical face and the technical back, are entangled, including in and/or through interstices of the fabric body toward the other of the technical face and the technical back. Raised fibers of the technical back are entangled, including in and/or through interstices of the fabric body, toward the technical face. The fabric body has a velour surface region formed at the technical back or the fabric body has a velour surface region formed at each of the technical back and the technical face.
According to another aspect of the invention, a double-face velour fabric article comprises a fabric body having a technical face formed by a filament stitch yarn and a technical back formed by a filament loop yarn or spun loop yarn, the filament stitch yarn comprising elastomeric material and the loop yarn comprising flame retardant material, the fabric body having a velour surface formed at one or both of the technical back and the technical face, and the fabric body having permeability of about 90 ft3/ft2/min or less under a pressure difference of xc2xd inch of water across the fabric body.
Preferred embodiments of both of these aspects of the invention may include one or more of the following additional features. The flame retardant material comprises m-Aramide fibers. The elastomeric material comprises spandex. The fabric body has permeability of about 70 ft3/ft2/min or less. Raised fibers of the velour surface of at least one of the technical face and the technical back is entangled, including in and/or through interstices of the fabric body toward the other of the technical face and the technical back. Preferably, raised fibers of the technical back are entangled, including in and/or through interstices of the fabric body, toward the technical face.
According to yet another aspect of the invention, a method of forming a velour fabric body comprises the steps of: joining a filament or spun loop yarn and a filament stitch yarn to form a fabric prebody, the filament stitch yarn forming a technical face of the fabric prebody and the loop yarn forming a technical back of the fabric prebody, the filament stitch yarn comprising heat sensitive material and the loop yarn comprising flame retardant material, finishing at least one of the technical face and the technical back of the fabric prebody, thereby to form a velour fabric body having at least one velour surface region, entangling raised fibers of at least one of the technical face and the technical back, including in and/or through interstices of the fabric body, thereby to increase density and tortuosity of the fiber body, the fabric body having permeability of about 90 ft3/ft2/min or less under a pressure difference of xc2xd inch of water across the fabric body.
Preferred embodiments of this aspect of the invention may include one or more of the following additional features. The method comprises the further step of entangling the raised fibers in a process of hydroentanglement, by directing fine, high-pressure jets upon at least one of the technical face and the technical back. The method comprises the further step of directing fine, high-pressure jets upon the technical back, to cause raised fibers of the velour surface of the technical back to entangle, including in and/or through interstices of the fabric body, toward the technical face. The filament stitch yarn comprises heat sensitive material, and the method comprises the further step of exposing said fabric body to heating sufficient to cause a response by the heat sensitive material, thereby to increase tortuosity. The method comprises the further step of entangling the raised fibers in a process of hydroentanglement, by directing fine, high-pressure water jets upon at least one of the technical face and the technical back. The method comprises the further step of directing fine, high pressure jets (e.g., water jets or air jets) upon the technical back, to cause raised fibers of the velour surface of the technical back to entangle, including in and/or through interstices of the fabric body, toward the technical face. The method comprises the step of finishing the technical face and the technical back of the fabric prebody, thereby to form a velour fabric body having velour regions at opposite surfaces. The method comprises exposing the fabric body to the heating sufficient to cause a response by the heat sensitive material during dyeing and/or during finishing. The method comprises exposing the fabric body to dry heat and/or to wet heat, e.g. steam or hot water. The method comprises exposing the fabric body to heating sufficient to cause a response by the heat sensitive material for about 2 minutes to about 60 minutes at about 212xc2x0 F. to about 450xc2x0 F. The method comprises exposing the fabric body to heating sufficient to cause a response by the heat sensitive material, thereby to increase tortuosity with a result of the fabric body having permeability of about 70 ft3/ft2/min or less. The method comprises joining a loop yarn and a filament stitch yarn, the filament stitch yarn comprising elastomeric material, e.g., spandex.
An objective of the invention is to provide velour fabric articles having flame retardance and improved dynamic insulation performance while avoiding increased weight and/or loss of stretch and/or loss of flexibility. A further objective is to provide velour fabric articles that may be worn in chilling, windy conditions without markedly diminished insulation performance. Generally, tortuosity, and therefore density, is increased by using heat-sensitive and/or elastomeric materials in the stitch yarns and entangling the loop yarn fibers. The improved dynamic insulation performance achieved in conditions of relative wind speed (i.e., wind blowing and/or movement of the wearer in relation to ambient atmosphere) enhances flame retardance properties by allowing less air to penetrate through the fabric construction. Thus flame retardance is enhanced, e.g. in accordance with very stringent flame retardance requirements of the protective cloth and military markets, e.g., as set forth in NFPA 1975-94 (the complete disclosure of which is incorporated herein by reference), by including fibers of inherent flame retardant material, e.g., m-Aramide fibers (NOMEX(copyright), as available from E. I. du Pont de Nemours and Company, of Wilmington, Del.) in the loop yarn of fleece or raised surface regions of the resulting velour fabric articles.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.